4/10/2017. Gazprom Neft has successfully applied the underbalanced drilling (UBD) technology that allows oil to be produced from a well while it is still under construction.

According to the company’s press service, the use of UBD technology in Gazpromneft-Vostok’s Archinsky field (Parabelsky District of the Tomsk Region) helped penetrate 15 additional oil-filled fractures, which is seven times more than the results provided by conventional drilling methods. The production rate of the new well — 160 t/day — is more than double the average of similar wells. It completely covers the costs of employing this complex high-tech solution.

Gazpromneft-Vostok produces oil from carbonate fractured reservoirs. Under such conditions, the productivity of wells depends on the number of natural fractures penetrated by drilling. The conventional drilling method implies that the drilling mud pressure in the hole is higher than the reservoir pressure. It makes the mud go into rock fractures and partially blocks the flow of oil into the well. In addition, it is impossible to continue drilling due to lost circulation, lost geosteering equipment signals, and the overheated drilling bit. Therefore, the conventional drilling method allows the penetration of only 1 or 2 fractures.

The use of UBD technology has solved the issue of lost circulation. The goal of the technology is to inject drilling mud with a pressure equal to or slightly lower than the reservoir pressure. This prevents mud loss. Ensuring a balance of pressure is a complex technological operation. To make this operation possible, it was necessary to mobilize equipment with a total weight of more than 400 tons that was in storage in Finland, the United Arab Emirates, and Iraq. Underbalanced drilling is more expensive than conventional drilling.

The opportunity to start production while a well is still under construction is another advantage. During the work in the Archinskoye field, 450 tons of oil have been extracted during drilling. It significantly increases the efficiency of operation of the field. The equipment used in this technology makes it possible to put wells into operation within just 2 days after completion. This is 8 times faster when compared to conventional drilling.

After the Archinskoye field operations, the company is about to test this technology in carbonate reservoirs of other fields operated by Gazpromneft-Vostok and Gazpromneft-Orenburg, as well as in East Siberia. The development of carbonate reservoirs is one of the nine areas of Gazprom Neft’s Technological Strategy.

A geophysicist by education, Aleksei Afonin has been working for 15 years as an offshore geophysical engineer, 13 years as a freelance technical translator, and 5 years as an SEO content writer. His experience as an engineer includes participation in large-scale hydrographic and seismic survey projects for oil and gas industry leaders such as Shell, British Petroleum, Chevron, Gazprom, etc. Geotechnical, geophysical, hydrographic/topographic surveys are his main areas of expertise in translation and writing. Owner of Russian Oil & Gas Translation Services (Reg. No. 316645100111016).